I. Field of the Present Invention
The present invention relates generally to fluid couplings, and more particularly to a head for mounting filters in fluid communication with the fluid conduit system.
II. Description of the Prior Art
Fluid systems often include filters which separate impurities and particulate matter from fluid flowing through the system to avoid clogging or excessive wear of parts in contact with the fluid system. Moreover, it is well known that the material removed from the fluid circulating in the system accumulates in a filter element and eventually interferes with flow of the fluid through the filter element. As a result, the filters are often removably mounted to a filter head so that they can be easily and quickly replaced when necessary.
It has previously been known to employ filter heads which are specially constructed so that a cannister holding the filter element can be threadably attached to and sealed against the head. As a result, the filter element can be replaced as necessary without disassembling the head or external cages for the filter element. Notably, since the fluid must be sealed within the filter casing during operation, means for selectively opening and sealing the container so that filter element can be removed can be quite complex and costly. Moreover, removal of the filter element alone which has been emerged in the fluid can be difficult and untidy. As a result, filter casings which are removable along with the filter element , thereby to avoid the problems of removing the filter element separately, require a head adapted to seal the filter element intermediate the inlet and outlet of the cannister.
One previously known form of removable casing is generally known as a spin-off filter. Previously known filter heads for securing spin-off filters in fluid communication with the fluid system are often specially constructed as a part of the machinery housing in which the fluid system is contained. Such incorporation can require substantial operations to be performed on the machine housing to adapt the housing to receive the easily removed spin-off filters. For example, the lubricating systems of internal combustion engines often employ a spin-off filter which mates with a filter seat specifically constructed on the engine block. Typically, the filter casing includes a threaded aperture as an outlet adapted to receive a threaded stem extending from the engine block. In addition, the filter head formed on the engine block must also include a machined surface adapted to engage a sealing ring between the end of the filter casing and the engine block. Of course, the formation of the filter head on the engine block requires substantial machining operations, which increase the cost of making the block. In addition, since the filter location cannot be altered when a filter head is formed on the engine block additional spin-off filters cannot be readily added to increase filtering capacity. In addition, it may not be possible to perform additional machining operations for forming additional filter heads on the engine block due to space restrictions or the position of adjacent equipment.
Moreover, although it has been known to form multiple filter heads so that additional filters can be included in a fluid circulation system, each such head requires individual stamping or casting, and machining and is particularly adapted to receive only a single spin-off filter. As a result, the addition of more than one additional filter to an existing fluid circulation system requires construction and installation of a filter head for each spin-off filter to be used.